Package org.apache.lucene.analysis.snowball

Class SnowballFilter

java.lang.Object

org.apache.lucene.util.AttributeSource

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.TokenFilter

org.apache.lucene.analysis.snowball.SnowballFilter

All Implemented Interfaces:

Closeable, AutoCloseable

public final class SnowballFilter
extends TokenFilter

A filter that stems words using a Snowball-generated stemmer. Available stemmers are listed in org.tartarus.snowball.ext.

NOTE: SnowballFilter expects lowercased text.

• For the Turkish language, see TurkishLowerCaseFilter.
• For other languages, see LowerCaseFilter.

Note: This filter is aware of the KeywordAttribute. To prevent certain terms from being passed to the stemmer KeywordAttribute.isKeyword() should be set to true in a previous TokenStream. Note: For including the original term as well as the stemmed version, see KeywordRepeatFilterFactory

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource

AttributeSource.AttributeFactory, AttributeSource.State

Constructor Summary

Constructors

Constructor	Description
SnowballFilter(TokenStream in, String name)	Construct the named stemming filter.
SnowballFilter(TokenStream input, org.tartarus.snowball.SnowballProgram stemmer)

Method Summary

Modifier and Type	Method	Description
boolean	incrementToken()	Returns the next input Token, after being stemmed

Methods inherited from class org.apache.lucene.analysis.TokenFilter

close, end, reset

Methods inherited from class org.apache.lucene.util.AttributeSource

addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, restoreState, toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

SnowballFilter

public SnowballFilter(TokenStream input,
                      org.tartarus.snowball.SnowballProgram stemmer)

SnowballFilter

public SnowballFilter(TokenStream in,
                      String name)

Construct the named stemming filter. Available stemmers are listed in org.tartarus.snowball.ext. The name of a stemmer is the part of the class name before "Stemmer", e.g., the stemmer in EnglishStemmer is named "English".

Parameters:

in - the input tokens to stem

name - the name of a stemmer

Method Detail

incrementToken

public final boolean incrementToken()
                             throws IOException

Returns the next input Token, after being stemmed

Specified by:

incrementToken in class TokenStream

Returns:

false for end of stream; true otherwise

Throws:

IOException